updated all of the compiler flags for the wheezy GCC

There were several new flags that are useful and a few that I've been
waiting for a good time to switch to, so I figured I'd do it all at
once.
diff --git a/aos/build/aos.gypi b/aos/build/aos.gypi
index 3f71412..bfb5234 100644
--- a/aos/build/aos.gypi
+++ b/aos/build/aos.gypi
@@ -65,6 +65,10 @@
       '-Wsign-compare',
       '-Wformat=2',
       '-Werror',
+      '-Wunused-local-typedefs',
+
+      # Give macro stack traces when they blow up.
+      '-ftrack-macro-expansion',
 
       '-ggdb3',
     ],
@@ -72,7 +76,7 @@
       '-std=gnu99',
     ],
     'cflags_cc': [
-      '-std=gnu++0x',
+      '-std=gnu++11',
     ],
     'include_dirs': [
       '<(DEPTH)',
@@ -82,13 +86,13 @@
           'cflags': [
             '-O0',
           ],
-          'ldflags': [
-            '-O3',
-          ],
         }, {
           'cflags': [
             '-O3',
           ],
+          'ldflags': [
+            '-O3',
+          ],
           'conditions': [['OS=="crio"', {
               'cflags': [
                 '-fstrength-reduce',
@@ -97,10 +101,7 @@
               ],
             }, {
               'cflags': [
-                # core2 says the same stuff as atom in the gcc docs but is supported by 4.4.5
-                '-march=core2',
-                '-mtune=generic',
-                '-msse3',
+                '-march=atom',
                 '-mfpmath=sse',
 
                 '-fstack-protector',
@@ -186,7 +187,7 @@
             '-m32',
           ],
           'defines': [
-            '_LARGEFILE64_SOURCE',
+            '_FILE_OFFSET_BITS=64',
           ],
           'libraries': [
             '-lm',
diff --git a/aos/build/externals.gyp b/aos/build/externals.gyp
index 0dcabf2..2bfee69 100644
--- a/aos/build/externals.gyp
+++ b/aos/build/externals.gyp
@@ -111,7 +111,9 @@
       'target_name': 'eigen',
       'type': 'none',
       'direct_dependent_settings': {
-        'include_dirs': ['<(externals)/eigen-<(eigen_version)'],
+        'cflags': [
+          '-isystem', '<(externals)/eigen-<(eigen_version)'
+        ],
       },
     },
     {